Objective Radiotherapy combined with conservative surgery plays an important role in the treatment of early-stage breast cancer. Volumetric modulated arc therapy(VMAT) has been introduced into clinical practice. The p...Objective Radiotherapy combined with conservative surgery plays an important role in the treatment of early-stage breast cancer. Volumetric modulated arc therapy(VMAT) has been introduced into clinical practice. The purpose of this study was to investigate the dosimetric effects of different multileaf collimators(MLC) on VMAT radiotherapy plans for treating breast cancer.Methods Fifteen breast cancer patients who were treated using a conventional technique in our department were selected to participate in this retrospective analysis. VMAT plans based on three types of Elekta MLCs [Beam Modulator(BM) with 4-mm leaf width, Agility with 5-mm leaf width and MLCi2 with 10-mm leaf width] were independently generated for each patient. Plan comparisons were performed based on dose-volume histogram(DVH) analysis including dosimetric parameters such as the homogeneity index(HI), conformity index(CI), Dmax, Dmin, and Dmean for the planning treatment volume(PTV), in addition to dose-volume parameters for the organs at risk(OARs). The delivery efficiency of the three types of MLCs was compared in terms of the beam delivery time and the monitor units(MUs) per fraction for each plan. Results Both target uniformity and conformity were improved in plans for Agility and BM MLC compared with the plan using MLCi2. The mean HI decreased from 1.14 for MLCi2 to 1.13 for BM and 1.10 for Agility, while the mean CI increased from 0.68 for MLCi2 to 0.73 for BM and 0.75 for Agility. Furthermore, at both low and high dose levels, smaller volumes of ipsilateral lung, heart, contralateral lung, and breast were irradiated with Agility MLC than with the other two types of MLCs. The delivery time with Agility MLC was reduced by 10.8% and 32.1%, respectively, compared with that for MLCi2 and BM.Conclusion Our results indicate that the Agility MLC exhibits a dosimetric advantage and a significant improvement in delivery efficiency for the treatment of breast cancer using VMAT.展开更多
OBJECTIVE Breast-conserving surgery has been a standard treatment for relatively small size of breast cancer. Younger breast cancer patients have more desire to conserve their breasts. This study was to investigate th...OBJECTIVE Breast-conserving surgery has been a standard treatment for relatively small size of breast cancer. Younger breast cancer patients have more desire to conserve their breasts. This study was to investigate the clinicopathological characteristics and prognosis of younger breast cancer patients who received breastconserving treatment in China. METHODS The data of 232 breast cancer patients who received breast-conserving treatment in Cancer Hospital of Chinese Academy of Medical Science from January Ist, 1999 to December 31st, 2005, were collected and retrospectively analyzed. According to the age, the patients were divided into 2 groups: younger group (age ≤ 35 at the time of diagnosis) and elder group (age 〉35). The clinical features of the patients in the 2 groups were compared, and their clinical characteristics, recurrence, metastasis and survival status were summarized. RESULTS In the 232 cases, younger patients accounted for 15.9% (37/232), the elder 84.1% (195/232). By December 2008, the median time of follow-up was 54 months (ranging from 2 months to 118 months). Two patients (5.41% , 2/37) in the younger group and 5 patients (2.56% 5/195) in the elder group died. The 5-year overall survival rate (OS) in the younger and elder groups was 96.08% and 97.19%, respectively (X2= 0.69, P = 0.4066). Local recurrence (LR) or distant metastasis (DM) presented in 5 patients (5/37, 13.51%) in younger group. LR or DM presented in 10 patients (10/195, 5.13%) in elder group. The 5-year disease-free survival (DFS) rate in the younger and elder groups was 82.58% and 95.52%, respectively (X2 = 4.02, P = 0.0451). Lymph node status and the age of 35 years old or younger were the prognosis factors affecting the DFS of patients who received breast-conserving treatment (OR = 3.467, 95%CI: 1.048-11.472, P 〈0.05; OR = 0.245, 95%CI: 0.069-0.863, P 〈 0.05). Lymph node status was the only prognostic factor affecting the DFS of younger group patients (OR = 7.357, 95%CI: 1.030-52.563, P 〈0.05). CONCLUSION Though the younger and elder patients have the same mid-long term survival rate, younger patients are more likely to have recurrence or metastasis than the elder patients. Breast-conserving surgery given to the younger patients especially to the younger patients with lymph nodes positive should be contemplated cautiously.展开更多
Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-...Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-dimensional conformal radiation therapy (3DCRT), two-step intensity-modulated radiation therapy (TS-IMRT) and direct machine parameter optimization intensity-modulated radiation therapy (DMPO-IMRT) after breast-conserving surgery. Methods: For each of 20 randomly chosen patients, 4 plans were designed using 4 irradiation techniques. The prescribed dose was 50 Gy/2 Gy/25 f, 95% of the planning target volume received this dose. The cumulated DVHs and 3D dose distributions of CR, 3DCRT, TS-IMRT and DMPO-IMRT plans were compared. Results: For the homogeneity indices, no statistically significant difference was observed among CR, 3DCRT, TS-IMRT and DMPO-IMRT while the difference of the conformality indices were statistically significant. With regard to the organs at risk, IMRT and 3DCRT showed a significantly fewer exposure dose to the ipsilateral lung than CR in the high-dose area while in the low-dose area, IMRT demonstrated a significant increase of exposure dose to ipsilateral lung, heart and contralateral breast compared with 3DCRT and CR. In addition, the monitor units (MUs) for DMPO-IMRT were approximately 26% more than those of TS-IMRT and the segments of the former were approximately 24% less than those of the latter. Conclusion: Compared with CR, 3DCRT and IMRT improved the homogeneity and conformity of PTV, reduced the irradiated volume of OARs in high dose area but IMRT increased the irradiated volume of OARs in low dose area. DMPO-IMRT plan has fewer delivery time but more MUs than TS-IMRT.展开更多
Axillary presentation from occult breast cancer is uncommon and continues to be a diagnostic and therapeutic challenge to physicians. Once the diagnosis of adenocarcinoma metastatic to an axillary lymph node has been ...Axillary presentation from occult breast cancer is uncommon and continues to be a diagnostic and therapeutic challenge to physicians. Once the diagnosis of adenocarcinoma metastatic to an axillary lymph node has been confi rmed, a preoperative workup should be done. The current experience is based on several relatively small retrospective reviews and case reports. It is diffi cult to determine the best management of occult breast cancer. However, treatment of axillary lymph node dissection is recommended for local control and complete staging information. Treatment of breast should be a choice between breast conservation with whole-breast radiotherapy and mastectomy. Adjuvant systemic treatment should be offered.展开更多
Cryopreservation techniques for mammalian oocytes and embryos have rapidly progressed during the past two decades,emphasizing their importance in various assisted reproductive technologies.Pregnancies and live births ...Cryopreservation techniques for mammalian oocytes and embryos have rapidly progressed during the past two decades,emphasizing their importance in various assisted reproductive technologies.Pregnancies and live births resulting from cryopreserved oocytes and embryos of several species including humans have provided proof of principle and led to the adoption of cryopreservation as an integral part of clinical in vitro fertilization.Considerable progress has been achieved in the development and application of the cryopreservation of mammalian oocytes and embryos,including preservation of the reproductive potential of patients who may become infertile,establishment of cryopreserved oocyte banks,and transport of oocytes and embryos internationally.However,the success rates are still far lower than those obtained with fresh oocytes and embryos,and there are still obstacles that need to be overcome.In this review,we address the major obstacles in the development of effective cryopreservation techniques.Such knowledge may help to eliminate these hurdles by revealing which aspects need improvement.Furthermore,this information may encourage further research by cryobiologists and increase the practical use of cryopreservation as a major part of assisted reproductive technologies for both humans and animal species.展开更多
文摘Objective Radiotherapy combined with conservative surgery plays an important role in the treatment of early-stage breast cancer. Volumetric modulated arc therapy(VMAT) has been introduced into clinical practice. The purpose of this study was to investigate the dosimetric effects of different multileaf collimators(MLC) on VMAT radiotherapy plans for treating breast cancer.Methods Fifteen breast cancer patients who were treated using a conventional technique in our department were selected to participate in this retrospective analysis. VMAT plans based on three types of Elekta MLCs [Beam Modulator(BM) with 4-mm leaf width, Agility with 5-mm leaf width and MLCi2 with 10-mm leaf width] were independently generated for each patient. Plan comparisons were performed based on dose-volume histogram(DVH) analysis including dosimetric parameters such as the homogeneity index(HI), conformity index(CI), Dmax, Dmin, and Dmean for the planning treatment volume(PTV), in addition to dose-volume parameters for the organs at risk(OARs). The delivery efficiency of the three types of MLCs was compared in terms of the beam delivery time and the monitor units(MUs) per fraction for each plan. Results Both target uniformity and conformity were improved in plans for Agility and BM MLC compared with the plan using MLCi2. The mean HI decreased from 1.14 for MLCi2 to 1.13 for BM and 1.10 for Agility, while the mean CI increased from 0.68 for MLCi2 to 0.73 for BM and 0.75 for Agility. Furthermore, at both low and high dose levels, smaller volumes of ipsilateral lung, heart, contralateral lung, and breast were irradiated with Agility MLC than with the other two types of MLCs. The delivery time with Agility MLC was reduced by 10.8% and 32.1%, respectively, compared with that for MLCi2 and BM.Conclusion Our results indicate that the Agility MLC exhibits a dosimetric advantage and a significant improvement in delivery efficiency for the treatment of breast cancer using VMAT.
文摘OBJECTIVE Breast-conserving surgery has been a standard treatment for relatively small size of breast cancer. Younger breast cancer patients have more desire to conserve their breasts. This study was to investigate the clinicopathological characteristics and prognosis of younger breast cancer patients who received breastconserving treatment in China. METHODS The data of 232 breast cancer patients who received breast-conserving treatment in Cancer Hospital of Chinese Academy of Medical Science from January Ist, 1999 to December 31st, 2005, were collected and retrospectively analyzed. According to the age, the patients were divided into 2 groups: younger group (age ≤ 35 at the time of diagnosis) and elder group (age 〉35). The clinical features of the patients in the 2 groups were compared, and their clinical characteristics, recurrence, metastasis and survival status were summarized. RESULTS In the 232 cases, younger patients accounted for 15.9% (37/232), the elder 84.1% (195/232). By December 2008, the median time of follow-up was 54 months (ranging from 2 months to 118 months). Two patients (5.41% , 2/37) in the younger group and 5 patients (2.56% 5/195) in the elder group died. The 5-year overall survival rate (OS) in the younger and elder groups was 96.08% and 97.19%, respectively (X2= 0.69, P = 0.4066). Local recurrence (LR) or distant metastasis (DM) presented in 5 patients (5/37, 13.51%) in younger group. LR or DM presented in 10 patients (10/195, 5.13%) in elder group. The 5-year disease-free survival (DFS) rate in the younger and elder groups was 82.58% and 95.52%, respectively (X2 = 4.02, P = 0.0451). Lymph node status and the age of 35 years old or younger were the prognosis factors affecting the DFS of patients who received breast-conserving treatment (OR = 3.467, 95%CI: 1.048-11.472, P 〈0.05; OR = 0.245, 95%CI: 0.069-0.863, P 〈 0.05). Lymph node status was the only prognostic factor affecting the DFS of younger group patients (OR = 7.357, 95%CI: 1.030-52.563, P 〈0.05). CONCLUSION Though the younger and elder patients have the same mid-long term survival rate, younger patients are more likely to have recurrence or metastasis than the elder patients. Breast-conserving surgery given to the younger patients especially to the younger patients with lymph nodes positive should be contemplated cautiously.
文摘Objective: The purpose of this study was to compare the dose distribution and dose volume histogram (DVH) of the planning target volume (PTV) and organs at risk (OARs) among conventional radiation therapy (CR), three-dimensional conformal radiation therapy (3DCRT), two-step intensity-modulated radiation therapy (TS-IMRT) and direct machine parameter optimization intensity-modulated radiation therapy (DMPO-IMRT) after breast-conserving surgery. Methods: For each of 20 randomly chosen patients, 4 plans were designed using 4 irradiation techniques. The prescribed dose was 50 Gy/2 Gy/25 f, 95% of the planning target volume received this dose. The cumulated DVHs and 3D dose distributions of CR, 3DCRT, TS-IMRT and DMPO-IMRT plans were compared. Results: For the homogeneity indices, no statistically significant difference was observed among CR, 3DCRT, TS-IMRT and DMPO-IMRT while the difference of the conformality indices were statistically significant. With regard to the organs at risk, IMRT and 3DCRT showed a significantly fewer exposure dose to the ipsilateral lung than CR in the high-dose area while in the low-dose area, IMRT demonstrated a significant increase of exposure dose to ipsilateral lung, heart and contralateral breast compared with 3DCRT and CR. In addition, the monitor units (MUs) for DMPO-IMRT were approximately 26% more than those of TS-IMRT and the segments of the former were approximately 24% less than those of the latter. Conclusion: Compared with CR, 3DCRT and IMRT improved the homogeneity and conformity of PTV, reduced the irradiated volume of OARs in high dose area but IMRT increased the irradiated volume of OARs in low dose area. DMPO-IMRT plan has fewer delivery time but more MUs than TS-IMRT.
文摘Axillary presentation from occult breast cancer is uncommon and continues to be a diagnostic and therapeutic challenge to physicians. Once the diagnosis of adenocarcinoma metastatic to an axillary lymph node has been confi rmed, a preoperative workup should be done. The current experience is based on several relatively small retrospective reviews and case reports. It is diffi cult to determine the best management of occult breast cancer. However, treatment of axillary lymph node dissection is recommended for local control and complete staging information. Treatment of breast should be a choice between breast conservation with whole-breast radiotherapy and mastectomy. Adjuvant systemic treatment should be offered.
基金supported by grants from the National High Technology Research and Development Program of China(2011AA100602)the National Science and Technology Major Project of China(2013ZX08007-004,2013ZX08008-004)the National Natural Science Foundation of China(31371486)
文摘Cryopreservation techniques for mammalian oocytes and embryos have rapidly progressed during the past two decades,emphasizing their importance in various assisted reproductive technologies.Pregnancies and live births resulting from cryopreserved oocytes and embryos of several species including humans have provided proof of principle and led to the adoption of cryopreservation as an integral part of clinical in vitro fertilization.Considerable progress has been achieved in the development and application of the cryopreservation of mammalian oocytes and embryos,including preservation of the reproductive potential of patients who may become infertile,establishment of cryopreserved oocyte banks,and transport of oocytes and embryos internationally.However,the success rates are still far lower than those obtained with fresh oocytes and embryos,and there are still obstacles that need to be overcome.In this review,we address the major obstacles in the development of effective cryopreservation techniques.Such knowledge may help to eliminate these hurdles by revealing which aspects need improvement.Furthermore,this information may encourage further research by cryobiologists and increase the practical use of cryopreservation as a major part of assisted reproductive technologies for both humans and animal species.